A wide range of refrigeratable dough products are currently available to consumers for producing numerous different baked products. These refrigerated doughs range from doughs for biscuits and breads to sweet rolls to cornbread products. These dough products are rather popular with consumers because they are very convenient and easy to use. Most of these products are sold in a pre-proofed state so that they can be opened to remove the dough and the dough can be baked immediately. Packaging and selling doughs in a pre-proofed state omits any necessity on the part of the consumers to carefully proof the dough for an extended period of time before baking it.
In producing refrigeratable dough products, suitably sized portions of unproofed dough are placed in individual containers. The dough is then proofed within the container, such as by holding the dough at an elevated temperature, causing the dough to expand. The dough will continue to proof until a positive internal pressure of about 15-20 psi is attained; most such containers will rupture or explode if the internal pressure of the container substantially exceeds about 40 psi. Such products are desirably capable of storage at refrigeration temperatures for at least a couple of weeks, and desirably as long as a few months, without any significant degradation of the quality of the dough or any substantial likelihood of having the containers rupture.
One disadvantage of refrigeratable dough products on the market today is that these doughs generally cannot be leavened with yeast. When yeast is used in a dough, the yeast cells will tend to continue to grow, or at least continue metabolization, even at refrigeration temperatures. The yeast therefore continues to produce carbon dioxide over the entire storage time, unless the dough is stored in a frozen state. Although allowing yeast to ferment for the entire shelf life of the dough may work if the dough is intended to be used immediately, extended storage (e.g. about two weeks or more) in a sealed container generally will not work because the pressure in the container will quickly build and rupture the container. If a conventional yeast-leavened dough were placed in a standard dough product container, the container may be expected to fail in no more than about two days. Additionally, continued activity of the yeast beyond the desired degree of proofing can deleteriously affect the organoleptic and rheological properties of the dough, producing unacceptable final baked products.
To date, manufacturers of refrigeratable doughs have had to replace yeast with chemical leavening agents, such as baking soda or the like. Such chemical leavening agents generally comprise a combination of a leavening acid and a leavening base, with the acid and base portions reacting to generate carbon dioxide, causing the dough to rise. One of the primary advantages of such leavening agents is that their behavior is based upon a predictable chemical reaction, permitting one to readily control the volume of carbon dioxide produced to leaven the dough. Once the chemical reaction of the leavening agents has proceeded to completion, carbon dioxide production ceases.
Although a chemically leavened dough product can be stored for extended periods of time at refrigeration temperatures, the final baked product obtained by baking such a dough is noticeably inferior to a product made with a yeast-leavened dough. Products made from yeast-leavened doughs are widely acknowledged to have superior taste, aroma and texture than those made with chemical leavening agents. Commercial dough manufacturers frequently add ingredients for the sole purpose of simulating yeast-leavened doughs. For instance, these manufacturers frequently add yeast flavoring, such as inactive pasteurized yeast cultures, to the chemically leavened dough. Even with such additives, baked products made from chemically leavened doughs lack the characteristic flavor and aroma of yeast-leavened dough and continue to exhibit relatively poor texture.
Others have attempted to solve the problems associated with storage of yeast-leavened doughs by storing the doughs at freezing temperatures rather than refrigeration temperatures. Frozen yeast-leavened doughs can yield baked goods which are noticeably better than chemically leavened refrigerated doughs. Yeast becomes inactive when frozen, thereby avoiding the problems associated with continued carbon dioxide evolution at refrigeration temperatures.
In a published European patent application (Published European Patent 0 442 575, published 21 Aug. 1991), Gist-Brocades describes a dough composition which uses a substrate limitation concept. In accordance with this disclosure, a dough is leavened with a maltose negative yeast (a yeast which cannot ferment maltose) and the dough is frozen. Gist-Brocades states that the dough may be thawed, proofed and baked anytime the same day without having to carefully monitor the proofing time. However, this dough is not designed by Gist-Brocades to be stored at refrigeration temperatures for extended periods of time, e.g. two weeks or more.
However, frozen doughs simply are not as convenient as pre-proofed refrigerated dough products. Whereas such refrigerated doughs can be baked immediately after removal from the container, frozen doughs must be allowed to thaw prior to baking. Also, since proofed dough does not survive freezing very well, frozen doughs generally must be proofed after thawing and prior to baking. This can further delay the baking of the dough. The consumer must spend more time monitoring the proofing process to avoid over-proofing the dough, making sure to place the dough in the oven for baking at the right time. Not only do such frozen doughs require more attention than do refrigerated dough products, it also requires the consumer to plan well in advance so the dough can be thawed and proofed to provide the baked goods at the desired time.
Hence, there has been a long-felt need in the industry for a yeast-leavened dough that can be stored at refrigeration temperatures for extended periods of time. To date, though, commercial producers have apparently been unable to make and sell refrigeratable yeast-leavened doughs suitable for large-scale commercial production and extended shelf life, despite the obvious economic potential of such a product. It appears that the problems associated with the continued generation of carbon dioxide by the yeast have precluded any such product.